Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence

Earthquake locations along the southern Mid-Atlantic Ridge have large uncertainties due to the sparse distribution of permanent seismological stations in and around the South Atlantic Ocean. Most of the earthquakes are associated with plate tectonic processes related to the formation of new oceanic...

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Published in:Journal of Geophysical Research: Solid Earth
Main Authors: Schlömer, A., Geissler, W., Jokat, W., Jegen, M.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2017
Subjects:
Online Access:https://gfzpublic.gfz-potsdam.de/pubman/item/item_5014937
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spelling ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5014937 2023-05-15T18:21:10+02:00 Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence Schlömer, A. Geissler, W. Jokat, W. Jegen, M. 2017 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5014937 unknown info:eu-repo/semantics/altIdentifier/doi/10.1002/2017JB015017 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5014937 Journal of Geophysical Research: Solid Earth info:eu-repo/semantics/article 2017 ftgfzpotsdam https://doi.org/10.1002/2017JB015017 2023-02-06T00:33:48Z Earthquake locations along the southern Mid-Atlantic Ridge have large uncertainties due to the sparse distribution of permanent seismological stations in and around the South Atlantic Ocean. Most of the earthquakes are associated with plate tectonic processes related to the formation of new oceanic lithosphere, as they are located close to the ridge axis or in the immediate vicinity of transform faults. A local seismological network of ocean-bottom seismometers and land stations on and around the archipelago of Tristan da Cunha allowed for the first time a local earthquake survey for 1 year. We relate intraplate seismicity within the African oceanic plate segment north of the island partly to extensional stresses induced by a bordering large transform fault and to the existence of the Tristan mantle plume. The temporal propagation of earthquakes within the segment reflects the prevailing stress field. The strong extensional stresses in addition with the plume weaken the lithosphere and might hint at an incipient ridge jump. An apparently aseismic zone coincides with the proposed location of the Tristan conduit in the upper mantle southwest of the islands. The margins of this zone describe the transition between the ductile and the surrounding brittle regime. Moreover, we observe seismicity close to the islands of Tristan da Cunha and nearby seamounts, which we relate to ongoing tectono-magmatic activity. Article in Journal/Newspaper South Atlantic Ocean GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Mid-Atlantic Ridge Tristan ENVELOPE(140.900,140.900,-66.735,-66.735) Journal of Geophysical Research: Solid Earth 122 12 10,427 10,439
institution Open Polar
collection GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
op_collection_id ftgfzpotsdam
language unknown
description Earthquake locations along the southern Mid-Atlantic Ridge have large uncertainties due to the sparse distribution of permanent seismological stations in and around the South Atlantic Ocean. Most of the earthquakes are associated with plate tectonic processes related to the formation of new oceanic lithosphere, as they are located close to the ridge axis or in the immediate vicinity of transform faults. A local seismological network of ocean-bottom seismometers and land stations on and around the archipelago of Tristan da Cunha allowed for the first time a local earthquake survey for 1 year. We relate intraplate seismicity within the African oceanic plate segment north of the island partly to extensional stresses induced by a bordering large transform fault and to the existence of the Tristan mantle plume. The temporal propagation of earthquakes within the segment reflects the prevailing stress field. The strong extensional stresses in addition with the plume weaken the lithosphere and might hint at an incipient ridge jump. An apparently aseismic zone coincides with the proposed location of the Tristan conduit in the upper mantle southwest of the islands. The margins of this zone describe the transition between the ductile and the surrounding brittle regime. Moreover, we observe seismicity close to the islands of Tristan da Cunha and nearby seamounts, which we relate to ongoing tectono-magmatic activity.
format Article in Journal/Newspaper
author Schlömer, A.
Geissler, W.
Jokat, W.
Jegen, M.
spellingShingle Schlömer, A.
Geissler, W.
Jokat, W.
Jegen, M.
Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
author_facet Schlömer, A.
Geissler, W.
Jokat, W.
Jegen, M.
author_sort Schlömer, A.
title Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
title_short Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
title_full Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
title_fullStr Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
title_full_unstemmed Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
title_sort seismicity in the vicinity of the tristan da cunha hot spot: particular plate tectonics and mantle plume presence
publishDate 2017
url https://gfzpublic.gfz-potsdam.de/pubman/item/item_5014937
long_lat ENVELOPE(140.900,140.900,-66.735,-66.735)
geographic Mid-Atlantic Ridge
Tristan
geographic_facet Mid-Atlantic Ridge
Tristan
genre South Atlantic Ocean
genre_facet South Atlantic Ocean
op_source Journal of Geophysical Research: Solid Earth
op_relation info:eu-repo/semantics/altIdentifier/doi/10.1002/2017JB015017
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5014937
op_doi https://doi.org/10.1002/2017JB015017
container_title Journal of Geophysical Research: Solid Earth
container_volume 122
container_issue 12
container_start_page 10,427
op_container_end_page 10,439
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